How do I get files and images to be uploaded to S3?

I have forked askbot-devel and adapted the lateast release (0.7.51) to run from heroku. Everything seems fine, with one exception: Heroku does not persist uploaded files, so even avatars or the new license symbol are lost after each application restart.

I suspect it is possible to have uploaded files sent to AWS (Amazon Web Services) S3 storage service. Changelog refereces that, Django documentation explains how to do it, but I can't find any reference in the code or documentation.